import axios from 'axios'
import { MessageBox, Message } from 'element-ui'
import store from '@/store'
import { getToken } from '@/utils/auth'


// create an axios instance 创建一个axios实例
const service = axios.create({
  baseURL: process.env.VUE_APP_BASE_API, // url = base url + request url
  // withCredentials: true, // send cookies when cross-domain requests
  timeout: 5000 // request timeout
})

// request interceptor 请求拦截器
service.interceptors.request.use(
  config => {
    // do something before request is sent 在发送请求之前做些什么
    // 修改请求头的一些参数配置

    if (store.getters.token) {
      // let each request carry token 让每个请求携带令牌
      // ['X-Token'] is a custom headers key 是自定义标题键吗
      // please modify it according to the actual situation 请根据实际情况修改
      // 这里的从 Cookies 中 获取一些数据
      config.headers['X-Token'] = getToken()
    }
    return config
  },
  error => {
    // do something with request error
    console.log(error) // for debug
    return Promise.reject(error)
  }
)

// response interceptor 响应拦截器
service.interceptors.response.use(
  /**
   * If you want to get http information such as headers or status
   * 如果您想要获得http信息，例如头或状态
   * Please return  response => response
  */

  /**
   * Determine the request status by custom code
   * 通过自定义代码确定请求状态
   * Here is just an example
   * 这里只是一个例子
   * You can also judge the status by HTTP Status Code
   * 您还可以通过HTTP状态代码来判断状态
   * 
  * 
   * 这里主要是为了统一数据请求回来的一些数据 的格式 使所有的返回数据格式保持统一 
   * 在前端页面 好管理
   */
  response => {
    const res = response.data

    // if the custom code is not 20000, it is judged as an error.
    // 如果定制代码不是20000，则判定为错误。
    if (res.code !== 20000) {
      Message({
        message: res.message || 'Error',
        type: 'error',
        duration: 5 * 1000
      })

      // 50008: Illegal token; 50012: Other clients logged in; 50014: Token expired;
      if (res.code === 50008 || res.code === 50012 || res.code === 50014) {
        // to re-login
        MessageBox.confirm('You have been logged out, you can cancel to stay on this page, or log in again', 'Confirm logout', {
          confirmButtonText: 'Re-Login',
          cancelButtonText: 'Cancel',
          type: 'warning'
        }).then(() => {
          store.dispatch('user/resetToken').then(() => {
            location.reload()
          })
        })
      }
      return Promise.reject(new Error(res.message || 'Error'))
    } else {
      return res
    }
  },
  error => {
    console.log('err' + error) // for debug
    Message({
      message: error.message,
      type: 'error',
      duration: 5 * 1000
    })
    return Promise.reject(error)
  }
)

export default service
